There are a number of situations which involve a need for hot ready-to-eat meals to be kept hot, for example for transportation purposes. To achieve that aim, it is possible to use a container of a heat-insulating nature. Such a container may typically be used for example by pizza baking establishments which produce pizzas in response to orders over the telephone, and then deliver the pizzas to the home of the customer.
In that situation, in the pizza baking establishment, the pizzas in the fully baked condition are removed from the respective baking tray and generally individually put into heat-insulating containers of cardboard, in which they are transported to and handed over to the customer. Containers of that kind for transporting pizzas and keeping them hot have been found to be comparatively expensive in practice as in fact they are only used once and in addition they have been found to be environmentally polluting as they must be disposed of, as waste. In addition there is the problem that a moisture-saturated atmosphere is formed in the interior of the closed cardboard container, emanating from the hot moisture-containing pizza, and that atmosphere softens the dough base of the pizza, which customers want to be crisp and crunchy, so that the enjoyment value is impaired.